


Protocol

by songofsongs



Category: Supernatural
Genre: Aromantic Dean, Destiel - Freeform, F/F, M/M, Sirens, Soulmates, Trains, i don't know anything about trains i'm so sorry
Language: English
Status: Completed
Published: 2016-01-10
Updated: 2016-01-10
Packaged: 2018-05-12 22:50:59
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 8
Words: 11,878
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5684026
Author URL: https://archiveofourown.org/users/songofsongs/pseuds/songofsongs
Summary: <blockquote class="userstuff">
              <p>Peter just wants to find Dean's soulmate, which isn't a problem except that it's impossible. Of course it ends up being Castiel's problem because when has luck ever been on his side? Meanwhile, Dean just really wants to take down a Siren.</p>
            </blockquote>





	1. Chapter 1

Castiel swept across heaven, leaving behind his training as he traveled to the head office of his garrison.  Naomi hadn’t explained why he was needed, only that it was “urgent” and he had to be there soon or he would “pay dearly.”  Hers were usually empty threats, but she wasn’t very pleasant to be around when she was unhappy.

            He landed neatly at the foot of the steps and walked into the building, turning down the long hallway where her office was located.  When he reached for the door he heard muffled voices and paused, then leaned his head against the door to listen.

            “He was so full of _good_ , you have to see for yourself!”

            “No really, I can probably just imagine it.”

            Castiel frowned.  He wasn’t sure if he should enter.  Would it be interrupting?  She did say “urgent.”  He decided it was a good idea to at least let her know he’d arrived promptly.  Probably.

            He knocked three times, and didn’t have to wait at all before Naomi shouted, “Come in, Castiel!”

            He pushed the door open to find Naomi sitting behind her desk, her clothing and posture impeccable as always.  In front of her, leaning over the desk but now looking over his shoulder at Castiel was a young Cupid Castiel had never before spoken to.  He did however, recognize his face.  Just last week the boy had gotten distracted cloud-watching while he was flying, had nearly collided with another angel, and instead veered out of the way just in time to smash into a building and fall into a decorative fountain below.  And that was just the most recent event.

            What could Castiel have possible done to deserve being in the same room as him?

            “I’m sorry, I could come back later if I’m interrupting.”

            Naomi relaxed slightly at seeing him.  “Oh no, I actually called you here to help out young Peter with a problem he’s having.” 

            Castiel frowned again, reaching for his sword and pulling it out a few inches.

            Peter straightened up with an affronted look.  Naomi rubbed her temples.

            “No no, no weapons necessary.  Peter why don’t you explain the problem.”

            Castiel wondered for a moment how he could possible help a Cupid if it wasn’t with his skills as a Seraph, but then all thought was halted as Peter started talking.

            It was unlike anything Castiel had ever experienced before, like someone had opened the clouds overhead and all the rain started pouring out in a waterfall, directly over his head.  Surely nobody needed to talk that _fast_.

            “It’s my day off so I thought I’d go visit the human world and just watch for a while, ya know?  So I see this human in a store in California, and Castiel, he’s beautiful.  But _something’s missing_.  I could see it in his eyes, his posture, his very breathing.  I think to myself, “This man needs something in his life.”  And what do humans love more than romance? Nothing, that’s what.  So I do my thing, I connect to his soul and BOOM! Nothing.  Something’s wrong Castiel, and I can’t rest until I’ve figured out what it is and fixed it.  When he’s happily laid eyes on the love of his life and found his purpose in life, then I’ll be able to go on with mine.  What do you say, Castiel?”

            Castiel’s eyes had glazed over sometime during the first sentence, or what he thought was the first sentence.  It was hard to tell where one ended and the next began when Peter didn’t so much as breath between words. 

            He looked over to Naomi, who was watching with a pained smile.  She’d probably already had to listen to this and more before he’d gotten here.  He took a moment to feel sorry for her before saying, “I still don’t understand why I’m being chosen for this?  Wouldn’t a higher level Cupid be more effective?”

            Naomi huffed.  “Of course they would, but they’re all booked for the day, and Peter here promised me that he wouldn’t rest until Mr…” she glanced at Peter.

            He looked at them blankly, then lit up and shouted, “Winchester!”

            “Yes, until Mr. Winchester has been matched.”

            Castiel only barely held himself back from asking, “Why me?”  Naomi seemed to be only holding onto her composure by a thread however and he wouldn’t be the one to break it.

            “Come on, Castiel.”  Peter bounced on the balls of his feet slightly.  “You’ve been stationed on earth plenty of times.  There’s gotta be something you could do to help.”

            He looked so certain and hopeful that Castiel knew he was doomed.  There was no way he could say no now.

            He cast a defeated look at Naomi.  “My training.”

            “Consider it taken care of.  I’ll inform Anael that you’re excused for the day.”  She suddenly seemed livelier, and she carefully shuffled papers around her desk with a pleased smile on her face.

            Peter bounced happily again and started tittering about how great it was to finish a job with “one of the soldiers” and “how much fun” they were both going to have together.

            Naomi interrupted him (thankfully) before he’d gotten too far by asking him to wait for Castiel in the hallway.

            He gave her a gummy smile and a thumbs up and practically pranced toward the door.

            “Peter?” she called after him.  When he turned back around she said, “Try not to touch anything.”

            He looked sheepish for just a second before he fixed another smile on his face.  “You got it, boss.”  Then he disappeared through the door with a sweep of dreadlocks and the swishy tan robes all the Cupids were required to wear. 

            Castiel tried compiling a list of synonyms for the word “swishy” so he’d never have to use it again when Naomi sighed and slumped down into her desk.

            His head whipped over to her just in time to see her place her head in her hands.  “We have a little problem Castiel.”

            He sighed too but waited patiently for her to ruin his day further.

            She held up a long piece of paper that curled toward the bottom and declared, “Dean Winchester doesn’t have a soulmate.”

            Castiel blinked.  He said nothing.  He blinked more and tilted his head.  “I don’t understand the problem.”  And really, he didn’t.  Some humans didn’t have soulmates.  He was under the impression that it was common knowledge. 

            “Peter isn’t fully trained yet.  His lessons haven’t covered aromantic people and I don’t have the authority to interrupt the flow of his studies.”

            “Couldn’t you…bend the rules a bit?  Just once?”

            She leveled him with a steady glare.  “I won’t be breaking protocol today, Castiel.  Peter’s convinced that Dean Winchester has a soulmate, but he’s probably just missing something else in his life.”

            “And I’m supposed to find it? That could be anything.”

            Naomi rolled her eyes.  “Isn’t it usually _something_ with humans? Like money? Or power? Or dogs?”

            Castiel could admire Naomi’s skill as a leader for days, and her ability to burn through paperwork with minimal breakdowns was unrivaled.  But there was a reason she didn’t deal with humans directly.

            “Human desires can be as diverse as they themselves are.  Unless he’s incredibly open to sharing his deepest desires with strangers I’m afraid there’s not much I can do.”

            “It’s worth a try.” 

            Castiel disagreed. 

            “I don’t have time to deal with him on my own, Castiel.”

            “If he doesn’t have a soulmate then it shouldn’t involve us at all.”

            Naomi shuffled her papers angrily.  “Well, Peter’s made it his problem, which makes it my problem, and I’m making it your problem so fix it.”  She tapped her papers down as if to make a point of ending the conversation, and Castiel didn’t bother arguing further.

            Especially when they both heard a loud crash from out in the hallway followed by a muffled, “Sorry!”

            Naomi took a deep breath and Castiel could hear the sadness in her voice when she said, “Castiel…please take your time down there.”


	2. Chapter 2

**Summary for the Chapter:**

> Peter just wants to find Dean's soulmate, which isn't a problem except that it's impossible. Of course it ends up being Castiel's problem because when has luck ever been on his side? Meanwhile, Dean just really wants to take down a Siren.

Dozens of people milled about the train platform, some kissing family members goodbye but most checking cellphones and trying not to make eye contact with anyone else.  A train whistle cut through the busy noise as Castiel and Peter stepped out of the station, followed by a robotic voice announcing that the next train would be departing for San Francisco in ten minutes.

            “-I just know you’re going to love him.  Probably immediately! He’s a bit rough, but he’s a gentle soul-“

            Castiel clapped a hand on his shoulder.  “Please stop talking.  At least until we find seats.”

            Peter pinched his first finger to his thumb and moved them across his tightly pressed lips before winking.  Castiel had no idea what that meant but the Cupid was no longer talking so he decided not to worry about it. 

            They managed to walk all the way to the train and climb aboard before Peter started tugging at the clothes he had switched into before coming to Earth and decided, “I don’t like collared shirts.  How do humans put stuff around their necks? I miss my robes.”

            Castiel sighed.  He’d been doing a lot of that lately.  On the other hand, he sympathized with Peter’s discomfort.  He himself would prefer to be back in his training gear than parading around in a business suit and coat.  Peter would get used to it someday, just like he’d gain grace and patience over the years.  Just like all the other Cupids.

            Castiel leaned toward Peter to whisper, “I don’t know where this human is, so you’re in charge of finding him.”

            Peter nodded.  “Consider it done, boss,” he said before immediately taking off down the train corridor, running his hands over each door as he went.  Castiel followed solemnly until Peter stopped abruptly outside of one carriage and whispered, “Found him.”

            Castiel was pleasantly surprised, having expected to spend much longer looking for the man.  He looked around them and tried to decide on the next course of action, but he was cut off mid-thought when he heard the door of the carriage slide open.

            “Hey!” Castiel jerked his head back to the carriage, where the man inside, Dean Winchester hopefully, was sitting up, alert, and yanking his duffle bag off the ground at his feet onto his lap.

            “Hi!” Peter responded.  “Can we sit in here with you?” he asked as he plopped himself down on the bench across from Dean.

            Dean looked at Peter in disbelief and Castiel finally stepped into the carriage, turning the man’s attention onto himself.  “Please excuse…my son.”

            Dean’s brow creased, even more confused now as he looked from Castiel’s vessel to Peter’s.

            Peter leaned back and grinned.  “I’m adopted.”

            “Oh.”  Dean seemed appeased for a moment but was still waiting for an explanation as to why they had barged into his train compartment when his eyes narrowed at Peter.  His eyebrows shot up and he pointed excitedly at the Cupid.

            “You’re the kid I saw in the store this morning!”

            “You recognize me?!”

            “Yeah, you’re the guy that knocked over that paper towel display.”

            Castiel would have interrupted here, or at least shot Peter a disapproving look, but he was too distracted staring at Mr. Winchester.  Peter hadn’t exaggerated.  By human standards he was attractive of course, but his soul was much more interesting, shining brightly onto every surface in the compartment.  The color reminded Castiel of how he felt after a long day of training, or a hard-fought battle, when all his garrison would pat each other on the backs and celebrate their hard earned break.  It reminded him of when one of his siblings would laugh, loudly and joyful.  It was the color he felt when he used to fly through the skies on his days off, swooping down to skim the oceans and back up to taste the atmosphere.

            It was warm, like home.

            “Did you see that lady’s face when the limes starting rolling towards her?”  Dean glanced over to Castiel, finally remembering he was there, and straightened up.

            “Well?  You gonna sit down or what?”

            Heat prickled up the back of Castiel’s neck.  He said nothing and simply sat next to Peter.  His eyes were probably colder than he meant, but he couldn’t help it.  He hadn’t even done anything wrong and already he managed to disappoint someone.  This was why he preferred to observe and not interact.

            Peter noticed the tense atmosphere Castiel was radiating and leaned away to give him some space.  “Sorry, Castiel’s not very sociable usually.”  He leaned in towards Dean conspiratorially and whispered, “Just be nice and he won’t bite.”

            Dean chuckled, and Castiel started to object to being talked about while he was in the same room, but then Dean was extending his hand in a greeting.

            “It’s nice to meet you, Castiel.  You’ve got a great kid.  Even stayed behind to clean up the store and everything.”

            Castiel took his hand, shaking it firmly as he’d learned was proper and smiled at Dean.  “That’s good to hear.  It’s nice to meet you too…”

            Dean stared and waited for him to finish his sentence for a moment before nodding in realization.  “Dean.  Dean Winchester.”

            As soon as he’d spoken the words a guarded look passed across his face, and his shoulders tensed minutely. 

            Peter, who had patiently been waiting for a break in the conversation payed no mind to the change and asked, “So, why are you heading to San Francisco?”

            Dean shook off the shadow that had passed over him, leaning back into the corner and propping one leg up on the bench on top of his duffle.  “A wedding.  My brother, Sammy’s.”

            “A wedding!” Peter jolted excitedly.  “I love weddings.  Don’t you?”  

            Dean smiled, bemused at the boy’s passion, and shrugged.  “A party’s a party.  At least once they get passed all the romantic crap.”

            Peter’s face fell immediately and Dean looked over to Castiel in distress.

            Castiel sat forward.  “You know, romance isn’t to everyone’s taste.  I’m not too fond of it myself.”

            Peter didn’t have much of a chance to respond as Dean shot him a grateful look and changed the subject immediately.  “What about yourselves?  What’s in San Francisco for you?”

            Castiel decided to let Peter tackle this one.  They’d gone over their cover story before-hand and Peter looked like he needed a distraction from his earlier disappointment.

            “Our family reunion is this weekend.  I haven’t seen my grandparents or any of my cousins in…it feels like forever.”

            Castiel couldn’t help but roll his eyes at the joke.  Peter went on about the trip and who would be waiting for them in San Francisco while Dean nodded sympathetically and looked at the watch around his wrist, probably noting how much time was left until they arrived.

            _Time._

Castiel still had to figure out what was ‘missing’ from Dean Winchester’s life, and whether or not he could provide it before the day was out.

            He looked at Dean, watching for any strange colorations in his soul, strange textures, areas that were too dim, anything that would alert him to something being wrong.  It was so bright though.  Looking at it directly too long became disorienting. Castiel had just started to notice a strange white film that had collected around Dean’s chest when he was interrupted by the man clearing his throat.

            “What’s up, Cas?  I got somethin’ on my shirt?”  He tugged at his flannel and gave Castiel an innocent look.

            Castiel was pretty sure that he was mocking him for staring but he didn’t want to call him out on it in case he was wrong.  Instead he answered, “No, sorry.  I just drifted off in my thoughts for a moment.”

            Dean nodded at him but didn’t look away, and Castiel held his gaze in turn.  Then the train whistle broke through their silence and the world outside started sliding past them.  Peter immediately turned to watch the people and buildings turn into a blur of colors and shapes.  Dean on the other hand glanced at his watch once again before standing up and stretching his arms above his head.  He picked up the duffel from the seat and opened the door to step outside.

            “I’m gonna be gone for a few minutes.  Just gonna talk to the conductor about something.”  Then he was gone.

            This time the silence didn’t even have a chance to exist before Peter was gushing about Dean.

            “Didn’t I tell you he was great?  His soul is like waterfalls and horse races and pine trees and pistachio ice cream.  I knew you would love him, Cas.”

            Castiel wasn’t sure what half of those things were but resolved himself to find out later.  He also noted with distaste that Peter had adopted the nickname Dean had given him, and allowed himself to hope that it didn’t follow him back to heaven.

            “Yes, his soul is beautiful.”  He held back from commenting on his less than pleasant manners because he and Peter seemed to get along so it was probably something Castiel had done.  “We can talk about it later, however.  We’re here on a job.”

            Peter nodded, sobering a bit.  “Did you see that white part around his chest? I saw you staring at it.”  Castiel nodded and he continued.  “Right, humans call that area the ‘heart chakra,’ or some do anyway.  The light they see coming from it usually gets labeled their ‘auras’ which I think is cool.  It’s like they can see their souls if they try hard enough, and they’re always making up words for things, sometimes things that we have words for too but they don’t-“

            “Peter,” Castiel interrupted. “Too much information I don’t need.”

            “Sorry.  Anyway, white stains on a human ‘aura’ usually means somethings wrong with that area.  In this case, the white around the heart chakra mean’s something’s wrong with his _heart_.”

            “That’s why you think it’s a soulmate.” Castiel breathed the words out quietly.

            “Of course it’s a soulmate.  What else would it be?”  Peter leaned back and propped his feet up on the bench across from them, crossing his arms over his chest.

            Castiel answered the question with one of his own.  “How do you usually help people find their soulmates, Peter?”

            He grinned.  “Easy.  It’s all in the soul.  It sort of…drifts in some direction and then I just follow it until I find who it’s pointing at.  Kinda like a compass.”

            Castiel nodded.  He’d never bothered to wonder how Cupids operated but that seemed simple enough.

            Peter sighed and leaned forward to place his head in his hands.  “But Dean’s soul doesn’t point anywhere.  It just sits there...shining in all directions.  I don’t know, Cas, maybe I’m just doing something wrong.”

            Castiel felt a pang of pity for the young angel, along with a pang of regret that there weren’t any higher level Cupids available to explain things to him. 

            “I’m sure it’s not you, Peter.”  He stood up and Peter stood up as well.  “Why don’t you wait here while I trail Dean and see if I can talk to him alone for a moment.”

            Peter sighed again but slumped back down into the seat.  “Don’t take too long.”

            “I promise to hurry if you promise to stay here and not talk to anyone.”

            Peter glared at him.  “I’m not a kid.”

            “You kind of are.  But mostly you’re a klutz, so just lay low for now.”

            Peter winced but shrugged in agreement and Castiel quickly left the carriage.  The hallway was deserted and most of the carriage doors were shut now that the train was moving.  Castiel followed in the direction Dean had moved towards earlier.


	3. Chapter 3

**Summary for the Chapter:**

> Peter just wants to find Dean's soulmate, which isn't a problem except that it's impossible. Of course it ends up being Castiel's problem because when has luck ever been on his side? Meanwhile, Dean just really wants to take down a Siren.

He crept slowly for a while, passing from one car to the next, when he got the idea to sense where Dean’s soul was located.  He stopped walking and reached out with his grace to feel for Dean’s presence, which surprisingly enough was only a few feet in front of him.  “Dean?” he called, stepping forward away from the carriages and into a small, dark enclave.  The bathroom was to his left and another door to his right, probably a closet of some sort, where Dean was hiding. 

            Castiel frowned in confusion.  He’d said he was going to talk to the conductor.  He most definitely wasn’t anywhere near the conductor.  Castiel thought back to the duffel bag Dean kept by his side like an I.V. drip, things just starting to click into place in his mind when the door flew open.

            Had Castiel not been deep in thought, he probably would have reacted more quickly.  As it was, Dean quickly had him pulled into the closet, slammed against the wall, and pressed a gun to his temple.

            He sighed.  Dean growled, pressing the pistol against him harder and gritting out, “I should have known you’d come after me.  The kid threw me off for a while but you, you’re not human.  The awkward, business man get-up was smart but you just couldn’t help but make yourself pretty, could you?”

            Castiel squinted and looked Dean up and down.  “Whatever you think I am, it’s not true.  I am flattered, nonetheless.”  He really wasn’t.  Mostly he was annoyed.  He should have recognized that Dean was a hunter.  This was going to complicate things greatly.

            “Don’t play dumb. Just tell me, is the kid a Siren too?”

            “Peter? No. And neither am I.  Even if I was, that gun wouldn’t kill me.”

            Dean chuckled and leaned in to whisper, “No but it’s gonna hurt real bad.”

            Castiel rolled his eyes.  “I don’t have time for this.  Look at that mirror, Dean.  Do I look like a siren?”  He motioned with his eyes toward their reflection in the metal walls around them.

            “What so I look away and you make a move?  Not a chance, buddy.”

            Castiel was about to protest when the closet door flew open once again in its second attempt to ruin his day. 

            Peter managed to tackle Dean to the floor, knocking the gun out of his hand which rattled to a stop under a shelf in the back.  Dean twisted trying to dislodge the cupid from where he was clinging to his back, not realizing Peter’s strength.  Castiel leaned down and together he and Peter maneuvered Dean until Castiel was holding his arms behind his back, still struggling and bucking wildly.

            Peter reached down and picked up the gun staring at it in his hands before looking back at Dean.  His eyes were hard with anger and a touch of hurt.

            “Why?” he asked, his words as hard as his eyes.

            “Listen, I don’t know what he said to make you do this but he’s not-“

            “Dean! Look.”  Castiel jerked him around until they were facing the wall of the closet, staring directly at their reflection.  Dean face quickly shifted from angry to shocked to sheepish as he looked as Castiel’s undeniably humanoid face in the wall.

            “Oh.”

            Castiel reluctantly let go of his hold on Dean, who immediately started rubbing his wrists.

            Peter cleared his throat and Dean’s head whipped back to him.

 “Man, I am so sorry.  This was all a huge misunderstanding.”  He took a deep breath and continued, “Look, I hunt things for a living.  And this is gonna sound crazy but, things that most people don’t think exist.”

            Peter gasped and looked downright scandalized.  “You wanted to shoot us because we’re angels?”

            Everyone froze.  Then all in one Cas groaned and Dean sputtered out, “ _What_?”

            “Oh…I think I missed something,” Peter concluded.

            “This is why you were supposed to stay in the carriage.”

            “Wait, wait! Can you repeat that, please?”  Dean asked.

            “I would but I really shouldn’t have said it in the first place.”  Peter looked down, embarrassed.

            “No you shouldn’t have.  That’s Rule Number One of dealing with humans.”  Castiel tried to use his best Stern Seraph voice.

            “You seriously expect me to believe you two are angels?”

            “I thought you knew! Why did you want to shoot Cas then?”

            “He’s hunting a Siren.  He thought it was me because he finds me attractive.”

            “I never said that!”

            “You like _Cas_?”

            Castiel frowned.  “You don’t need to sound so surprised.”

            “I don’t like Cas!” Dean yelled it, throwing his hands up for emphasis and causing both the angels to glare at him.

            “Why are you yelling, man? You’re gonna bring unwanted attention.”

            Dean sighed and dropped his hands so he could rub his temples.  “Look. I’ve been tracking this siren for almost a week.  Three people have died so far and I know that it’s on this train somewhere.  So I would really like it if one of you – not you!” he said as Peter opened his mouth, “to tell me why there’s apparently two angels following me.”

            Peter breathed deeply.  “Can I please tell him, Cas?”

            “No.  This is why I came after him in the first place.  You should go back and wait in the carriage.”

            The excitement drained visibly from Peter’s face and he slowly slinked past them into the corridor, muttering about getting to do ‘his own job’ sometime today.

            When he was gone Cas turned to Dean and with no fanfare announced, “You don’t have a soulmate.”

            Dean stared at him blankly before nodding.  “Great to know.”

            Castiel sighed.  “You don’t understand.  Peter thinks that you have a soulmate, that everyone does actually, and he’s not gonna stop until we find yours.”

            Dean looked incredulous and Castiel added, “He’s a Cupid.  A very new Cupid who cares way too much.”

            “So just tell him I don’t have a soulmate and then you can leave me alone.”

            “Yes,” Castiel bit out.  “That would work.  Except I can’t tell him that.”  When Dean started to interrupt Castiel held his hand up.  “It would be considered interfering with his lessons, which only other Cupids are allowed to do.  It’s protocol.”

            “ _Protocol_?  Cas, people are dead.  Another person could be dying right now.  I don’t have time to deal with your heavenly lesson plan.”

            “There is a way we can get through this quickly but you’ll have to cooperate.”

            Dean watched Cas’s face cautiously, then said, “Fine.”

            “There’s…something here,” Castiel said, pointing at Dean’s heart.  “Something in your soul.  It’s not good.”

            Dean looked back up at Castiel with a sour look on his face.  “Wow.  Tell a guy how you really feel, Cas.”

            And there it was again.  That tone of voice that just dripped in sarcasm and made Castiel wanna fly back to heaven and never return.

            “Fine.”  He stepped closer to Dean, intentionally invading his personal space and not looking away from his eyes.  “I was pulled away from my training this morning in order to team up with a fledgling that talks too much to try and give you whatever it is you want most in the world.  Judging by that white stain around your chest, you are missing something, and it’s making you sick.  All the way down to your soul.  So if you want us to leave you to your hunt, I need you to tell me exactly what it is that’s missing in your life.”

            Dean held Castiel’s eyes through the whole speech and started squirming uncomfortably as it continued.  Castiel noted that last bit with a touch of satisfaction.

            “I mean – I’m not gonna pour out my soul to some dude I just met on a train.”

            Castiel couldn’t help it.  “Well, you’ve already admitted you’re attracted to me so what’s the harm.”

            Dean spluttered.  “I never said that!”

            “You did. Kind of.”

            “I said you were good-looking and that’s all.”

            Castiel hm’d. “You thought I was the siren, and that I was ‘coming after you,’ and since siren’s ‘go after’ people by becoming what they want most, you definitely implied that I’m –“

            “You know what? This isn’t important!”  Dean’s cheeks were flushed and he wouldn’t meet Castiel’s eyes anymore. 

            Castiel decided that human’s weren’t so bad to be around as long as you knew how to get under their skin. Or perhaps it was just Dean that made this whole event so satisfying.


	4. Chapter 4

**Summary for the Chapter:**

> Peter just wants to find Dean's soulmate, which isn't a problem except that it's impossible. Of course it ends up being Castiel's problem because when has luck ever been on his side? Meanwhile Dean just really wants to kill a siren.

Dean stared to say something else, presumably to change the subject, but he was cut off by a loud shriek that echoed down the hallway outside.  The two of them locked eyes for just a second and then they were racing down the train toward the sound.

            By the time they’d gotten to the scene a group of people had already gathered around, whispering sharply and covering their mouths in horror.  Dean and Cas pushed through the throng until they made it to the opening of one of the train carriages, where a woman was holding a man’s bloody corpse and weeping.  The sight made Castiel’s stomach twist and tears prick in his eyes.  He realized, quite suddenly, that kneeling behind the couple was Peter.

            Peter was gently running one hand through the woman’s red hair and whispering quiet reassurances.  Tears were cascading down his cheeks like the waterfalls he’d mentioned earlier, and Castiel was harshly reminded that Cupids were not accustomed to death.  Especially not one so gruesome as this.

            “Out of the way!”  A train attendant pushed through the group clogging up the hallway and gasped as soon as she saw the couple on the floor.  She stared in shock for a moment before steering herself and facing the crowd again.  “You all need to leave.  Go on, back to your carriages.  We’ll have you all updated as soon as this is taken care of.”  She started to shoo the crowd back with firm hands even though her voice wavered.  The crowd began to disperse reluctantly with whispers of, “Do you think they’ll stop the train,” and, “That poor woman.”

            Behind her the woman was now choking out broken bits of sentences in between sobs.  Castiel caught something that sounded like, “Why did she make me do this?”  It was difficult to make out her words around her gasping breaths and wails.

            All the while Peter cried and comforted her.

            “Excuse me, I’m sorry but you have to leave.”  Castiel’s attention was brought back to the attendant as she tried to guide him and Dean away from the carriage.

            “Oh, we’re with the boy,” Castiel said.  The attendant whipped back around and stared at Peter as if she hadn’t even noticed him before.  It was possible that she hadn’t.

            “How old is he?” she asked quietly.

            Castiel glanced at Peter, trying to guess how old his vessel appeared to humans.  He settled on an age young enough to convince the attendant to let them stay with him.  “Seventeen.”

            She dropped her head down for a moment before looking back up at Castiel.  Her voice sounded pitiful but resolved when she said, “I’m so sorry you’ve all been caught up in this.  Especially somebody that young.  You can stay with your son.”  She addressed the last part to both of them, and for a second Dean looked like he was going to correct her assumption.

            Instead he politely smiled and thanked her.  More attendants appeared now, each taking a moment to stare at the bloody scene in horror, and one rushing off when it was too much to handle.  Two of them gently pried the woman away from her husband, pleading with her to cooperate when she clung to him.  His blood covered most of her available skin, including much of her face, and Castiel ached knowing that she would have to wash her husband’s blood down the drain.

            When they had successfully removed her from the carriage, she switched from clinging to her husband to clinging to Peter, who was still providing words of comfort through his own tears.  One attendant led them towards the front of the train as another slid the carriage door shut.

            He turned towards the attendant that had appeared first and said, “We can’t touch anything.  I’ll get the cops on the phone and let the conductor know what happened.”

            The first attendant nodded, more composed now that time had passed.  “I’ll start talking to the passengers.  Try to answer some of their questions.”

            “Maybe we should wait until we have more answers to their questions,” he said.

            “Okay.”

            The other attendant noticed Dean and Castiel standing off to the side listening to the conversation.  “What are you two still doing here?”

            The first attendant stepped between them, saying, “It’s fine.  I’ll take care of them, just go talk to the conductor.”

            He nodded and turned to walk down the corridor.  In his absence the attendant rubbed her hands down her face and took a deep shuddering breath.

            Dean stepped forward and placed his hand on her shoulder.  “Hey, you gonna be alright?”

            She sniffled and nodded, turning to face them both again.  “It’s just…I’ve seen a lot of strange things in my career, but I’ve never seen someone…kill her husband.  And she sounded so sorry.  I mean what would possess someone to do something like that?  Just in the heat of the moment?”

            Castiel noted the appropriate word choice.  Possession was basically how it felt to be under the spell of a siren.

            “How long have you worked here?”

            The woman thought for a moment, and Castiel wondered why Dean had asked that question in the first place.

            “Six years.  I tried to be a stewardess before, but I found out that I don’t do well with heights.”

            Dean laughed.  “Yeah, I’m with you there.”

            She smiled at him.  “Bad experience on a plane?”

            “You can say that again.”  The two of them smiled at each other for a moment, and that was all the time it took for Castiel to understand what was happening.  Dean wasn’t trying to get information, wasn’t even thinking about the case right now.  He was taking her mind off the death and bringing her back into a sense of normalcy.

            Castiel remembered once in Egypt, watching a woman distract her young granddaughter from the violent winds that shook their house.  He remembered a teenage girl in Morocco singing to her younger brother after he witnessed another student trip and badly injure himself at school.  He remembered every moment he’d glimpsed just how deep human compassion ran and how freely they handed out moments of pure love for one another.  He remembered Peter murmuring words of comfort to the woman in the carriage.

            “Why don’t we talk somewhere else?” Castiel suggested, and they all looked somberly at the closed carriage doors.

            They moved down the hallway, in the direction the other attendant had gone, and she told them her name was Janelle.  Castiel asked when they would be allowed to see Peter.  She said they had no authority to hold him since he wasn’t involved in the murder, but she would have to ask the conductor to be sure. 

            “He had nothing to do with any of this.”

            Janelle smiled at him reassuringly.  “I believe you.  I can’t make any promises until the cops get involved though.”

            When they got to the end of the train Janelle stepped into the cab and left Dean and Cas to themselves.  As soon as they were alone Dean’s calm demeanor dropped, his fists clenched, and all the muscles in his shoulders tightened visibly.

            “Dean.”

            “Don’t say anything.”  Dean’s voice was tight, his anger barely controlled.  He took a few deep breaths and then said, “This shouldn’t have happened.  I could have stopped this if you hadn’t distracted me.”

            Castiel didn’t say anything.  He watched as Dean’s soul swirled around violently and shrank in towards himself.

            “God, what if they have kids? That lady’s gonna go to jail for a crime that wasn’t her fault and those kids are gonna lose both their parents in one day, all because you and Peter wanted to play matchmaker!”

            Castiel stepped forward, grabbing Dean by the shoulders and forcing him to look him in the eye.  “Don’t bring Peter into this.”  He could hear how dark his voice had become, dropping lower and the air around them vibrated as Castiel’s grace sent out a wave of anger.

            Dean froze as he sensed the power radiating from Cas and jerked out his grasp.  Cas let him go.

            “What do you really think you’ll get from blaming anyone for this?  At the end of the day the one who’s causing this is the creature you’re hunting.  But you’ll still go to bed every night hating yourself over it.”

            Dean took in a sharp breath and looked away.

            “That’s it, isn’t it?  You think everyone in danger of a supernatural death is your responsibility because you’ve made some personal oath that you’ll dedicate your life to saving them.”  Dean still wouldn’t look at Cas so Castiel stepped around him so they were facing.  “You can’t Dean.  You can’t save all of them.  Humans die all the time.  You’ll drive yourself mad trying to stop it.”

            Dean looked up at him, fury written in his eyes.  “You just want me to stop caring? Stop trying?”

            The doors to the cab opened and Janelle stepped out again, with another woman behind her.  The tension between Dean and Cas dissipated quickly at their arrival as both adopted an air of patient concern. 

            “Gentlemen, thank you for waiting.  This is Lin, the train conductor.” 

            Lin stepped forward and thrust out her hand for Dean to take.  “Nice to meet both of you.  So sorry to hear about the tragedy you witnessed, but I promise you don’t have anything more to worry about.”

            Both of them knew that wasn’t true but stayed quiet on the matter.  Cas took a moment to familiarize himself with her.  Average height, light brown eyes, a bit on the thin side, Chinese American with a strong Irish accent.  He took a mental note to ask how long she’d been living here if he needed to make casual conversation.

            Dean took her hand and with a charming smile said, “Nice to meet you too, Lin.  Quick question, if you’re the conductor, who’s driving the train?”

            Lin laughed.  She shook hands with Cas, who gave her a polite smile and nod, and said, “I don’t actually control the train.  I’m more like a supervisor.  No, that job goes to the train engineer, Martha.”  She spun around and opened the door of the cab again.  They all looked inside to see a short, stocky Hispanic woman manning the controls.  She turned around at the sound of the door and took in the sight of them.  Then she smiled a toothy grin and saluted them.

            Dean saluted her back and Cas gave a small wave. 

            “Yeah, that’s my right hand gal right there.”  She smacked the wall with her hand a few times and the two of them shared a small smile.  Martha’s eyes seemed to grow soft and focus behind all of them, and Cas glanced back to see Janelle smiling fondly at her.  He looked back into the cab but the engineer had turned back to her controls and Lin shut the door.

            She quickly grew serious.  “So, I hear it was your boy that decided to play the hero earlier.”  Janelle shot her a questioning look and she said, “Marcus filled me in before you got here.  I can take you to him now if you’d like.”

            “Please.” Castiel chimed in.

            “Oh, he does speak,” Lin said, making her way towards the end of the car.  “Voice is a bit deeper than I expected.”

            Dean snorted, Cas squinted, and they all followed after her.


	5. Chapter 5

**Summary for the Chapter:**

> Peter just wants to find Dean's soulmate, which isn't a problem except that it's impossible. Of course it ends up being Castiel's problem because when has luck ever been on his side? Meanwhile Dean just really wants to take down a siren.

Lin stopped the group not too long after and slid open the doors to one of the carriages.  Inside, Peter was sitting on one bench with his legs tucked under him and a full glass of water in his right hand.  He was staring out the window as the scenery passed by and jumped up as soon as the doors opened.  On the opposite bench the attendant from earlier, Marcus, sat quietly.

            “Castiel!”  Peter rushed forward, stopping to awkwardly hand the untouched glass of water to Marcus, and then wrapping his arms around Castiel’s waist. 

            “Um.”  Castiel brought his hands up and placed them on Peter’s back, not sure if he should pat or rub or just hold him but settling on the last option.  “Are you okay?”

            Peter nodded, then whispered, “They wouldn’t let me stay with her.”

            Castiel pulled back and looked over to Lin.  “Where are you keeping the woman?”

            “She’s being kept in a compartment of her own.  It’s protocol.”

            “Do you think I could talk to her alone?” Dean asked.

            Lin pursed her lips.  “She’s not supposed to talk to anybody.”

            “Don’t you think you could…bend the rules?  Just between us of course.”  Lin didn’t look convinced and Dean hurried to add, “It’s just…she lost her husband, and I think she could use somebody to talk to, you know?”

            “He’s got a point,” Janelle piped up from the back of the group. “And if anyone can make her feel better it’s probably him.”  She smiled at him softly.  “If nobody said anything, there would be no harm done.”

            Lin sighed.  “Alright.  But this is the only time I’m bending the rules for ya, and one of my attendants is gonna stand watch.  Got it?”

            Dean saluted her and she rolled her eyes.  Marcus led Dean to a compartment further down the corridor and they watched him step inside and shut the door behind him. 

            “Nice locks,” Peter said, grinning and nodding to the dreadlocks Janelle had pulled back into a neat bun sitting beneath her attendant’s hat.

            Janelle smiled.  “Thanks.  Yours too.”

            Peter reached up to run his hand through his own dreadlocks and pulled a strand forward to look at.  “I think mine are too short.  I couldn’t put them in a bun like that.”

            “Hey,” Castiel interrupted softly.  “Can I talk to my son alone for a while?”

            “Absolutely,” Janelle answered.  Peter was already moving into the train carriage, sitting down on the same bench as before. 

            Cas followed him in, shutting the door and sitting down across from him.  Before he could even say a word, Peter was talking.

            “I’m sorry.”

            “What?”

            “I left the carriage after you said not to.  I understand if you’re mad.”  He stared down at his hands folded in his lap.

            Castiel sighed and scooted forward so he was closer to Peter.  He waited until Peter looked up at him to talk.

“You didn’t do anything wrong.  Actually, you did everything right.  You should always help people when you can, and what you did was incredibly kind.  And brave.  And I’m going to make sure Naomi hears about it all when we get back home.”

            Peter smiled shyly.  “So you forgive me for disobeying orders?”

            “Yes.”

            “And for telling Dean we’re angels?”

            Cas paused.  “Yes.”

            Peter breathed out a sigh of relief and leaned back in his seat comfortably.  “That’s good to hear.”  His voice grew quiet as he added, “I like you, Castiel.  I want to be friends when we get home.”

            “Of course we’re friends,” Castiel said.

            Peter’s eyes lit up.  “Cool.  I’ve never had one of those before.”

            Castiel felt like he’d been punched in the stomach, but before he could say anything the carriage door slid open and Dean joined them.  He glanced from one side of the small area to the other before deciding to sit next to Castiel.  Castiel felt a touch of unexpected pride at it and slid over to give Dean more space.

            “How you doin’, Peter?” 

            “I’m good.  You?”

            “Could be better.  By the way I’m your dad now.”

            Peter cocked his head to the side and looked curiously at Castiel.

            “That’s what the attendant assumed and neither of us had the heart to correct her,” he explained.

            “Oh.”  Peter looked back out the window for a moment and then turned his attention fully back to them.  “Dean were you lying about the wedding?”

            Dean leaned back in surprise.  “Well, yeah. Kind of?  My brother lives in New York, and the only reason I’m on this train is because the Siren is.”  Peter nodded, his eyes looking blankly past them.  “If it makes you feel better, he is getting married in a few months.”

            Peter’s face did light up a bit at that.  “Can I come?”

            “To the wedding?” Dean sounded amused.  “I’ll tell you what: If we take down this siren before it takes another person I’ll call tonight and ask if I can bring a guest with me.”

            “Two guests,” Peter corrected and smiled at Castiel.

            Castiel shook his head.  “It’s okay.  I’m probably busy that day.”

            Peter sighed and looked like he wanted to protest but Cas turned to Dean and asked, “Did you learn anything from the victim?”

            Dean quickly deflated.  “Nothing I hadn’t already figured.  She’s on vacation with her husband of sixteen years, gets up to go to the bathroom.  On the way back she runs into this woman, ‘ _the most beautiful person I’ve ever laid eyes on_ ,’ and the next thing she knows she’s standing over her husband’s corpse holding a knife that she definitely didn’t bring onto the train.”  He sighed and rubbed the bridge of his nose.  “That woman knows her life is over.  I promised her I’d take down the sucker that did this, and as far as we know, it could be anyone on the train.”

            “Well…we can cross quite a few people off the list actually,” Cas responded.

            Dean raised his eyebrows. 

            “I got a good look at everyone in the crowd that gathered around the scene earlier.  It wasn’t any of them.  Also none of the train staff that we’ve seen so far.  None of us obviously.”

            “Wait, whoa, back up for a sec.  How do you know it wasn’t any of those people?”

            “Cause sirens are ugly and easy to spot,” Peter answered, staring out the window again.

            “You guys can see the Siren’s true face?”  Dean sounded impressed.  Cas and Peter both nodded.

            “Well that makes this a helluva lot easier.”  Dean relaxed for what seemed like the first time this whole trip.  “Now we just need to find a way to figure out who the siren infects before they can kill anybody and borrow a bit of their blood and boom, job done.”

            “I have a feeling it won’t be that simple, but your confidence is comforting,” Cas said.

            “What do we do now?” Peter asked.

            “Well,” Dean said patting down each of his pockets, “the only way we can kill it is with a bronze knife.”  He hung his head.  “Which I left in my duffel back in that closet.  Sloppy, Winchester.”

            Peter shrugged.  “So we get the knife back.  No big deal.”

            “It has to be coated in the blood of one of its victims.  Someone currently under its spell.”  Castiel racked his brain for more information he had on sirens.  “The woman from earlier…she’s not gonna work is she?”

            Dean frowned.  “No…I don’t think she’s under the spell anymore.  Which doesn’t make any sense.”  He shook his head.  “I’ve never seen a Siren’s spell wear off that fast in my life.  It usually takes hours, or until the thing is dead.”

            “New breed of Siren?”  Peter suggested.  Then he smirked and whispered, “They’re evolving!”

            Castiel chuckled at the reference.  Dean looked at them blankly.

            “That was what the Archangel Raphael said when he first saw sea creatures crawling out onto the land all those years ago.  Or that’s what I hear.  You should ask Cas, he was there.”

            Dean’s eyebrows shot up towards his hairline.  “That…makes you pretty old.”

            Dean and Peter were now both staring at Castiel expectantly, as if waiting for some detailed recounting of the Days of Yore.  He shuffled under their gazes and said, “Why don’t we just focus on the case for now?”

            Dean nodded and cleared his throat, leaning forward.  “So here’s the plan.  You guys are gonna check out every compartment, every room, every closed door until you find this thing.  There’s only so many places it can be hiding.” 

            Cas shook his head.  “There’s many places it could be hiding.  Plus, the second it sees on of us, it’ll be able to tell we’re angels.”

            “Well don’t have to look directly at it!” Peter said.  “I’ll just sense where it’s hiding, like I did this morning to find Dean.”

            Dean looked vaguely uncomfortable at the fact that he’d been stalked onto the train but shook it off and continued.  “Great.  You two find the thing, and then,” he looked at Cas speculatively.  “Is it possible – I mean like…can you,” he gestured vaguely with his hands.  “Could you make yourself invisible to it?”

            Castiel’s lips turned up and he decided rather than telling Dean, he would just show him.

            Dean’s eyebrows returned to his hairline and Castiel smiled fully this time. 

            “Oh, good.  That answers that, then.”  He waited patiently for a moment and then sighed.  “Come on Cas.  I get it, cool superpower.  Come…back?”  He waved his hand through the spot Cas was sitting, hitting what no doubt felt like open air.  Peter coughed into his sleeve to hide a laugh.  Castiel stood up and moved to the opposite bench, sitting down next to Peter.

            “This isn’t funny, Cas.  We have things to do.”

            “Sorry,” Cas said, revealing himself from his new seat.  Dean jumped and pointed an angry finger at him.

            “Don’t do that again.”

            Peter was laughing loudly now, no mistaking it, and Dean frowned at him as well.  “Okay Houdini, once we find the thing, you’re in charge of tracking it.  I’ll get you the knife.  Keep it on you.  Wait until it infects someone and coat the thing in their blood.”

            “That does sound pretty simple.  Where will you two be staying?”

            “We’ll be close by in case something goes wrong.”  Dean stood up.  “I'll be right back.”

            “I got it,” Peter said, handing the whole duffel over to Dean.  Dean took the bag numbly and stared at him in confusion.

            “When did you get this?” he finally choked out.

            “Oh, just now when you guys were talking,” he said casually as if they were discussing something as trivial as the weather.

            “What, you guys can teleport now?”

            “Technically we always could,” Cas said.  “Actually, if you’re not too set on doing this the old fashioned way I could always fly the siren to the sun.”

            Dean nodded dumbly.  “Yep…yeah that would work.”  He looked thoughtful for a moment and then decided, “Actually, no.  I’m gonna have the satisfaction of watching it die, myself.”

            “You’re going to add unnecessary risk by having another person infected for your own personal vendetta?”

            Dean shot him a hard glare.  “That thing has been taunting me for a week.  You think it killed that man today because it felt like it?  No.  It knows I’m here and it’s pissed that I managed to track it this long.  It’s gonna kill again, soon, and I told Evelyn I would kill it for her.  So I will.”

            Castiel assumed Evelyn was the woman who’d killed her husband and decided not to argue further on the matter. 

            Apparently Dean was following a protocol of his own now.


	6. Chapter 6

**Summary for the Chapter:**

> Peter just wants to find Dean's soulmate, which isn't a problem except that it's impossible. Of course it ends up being Castiel's problem because when has luck ever been on his side? Meanwhile Dean just really wants to take down a siren.

Dean and Cas waited in the same closet as before for Peter to return, and Castiel was starting to worry.  It hadn’t taken him long to survey his half of the train, and Peter was well-versed in the art of reading the human soul.  He should have been back by now.  Neither he nor Dean spoke.

            Just when Cas had decided to go after him, Peter appeared.  Dean jumped, still not accustomed to the ‘teleporting thing’, as he put it.

            “I found it.”  Peter whispered.  “Compartment F7.  Hurry up!”

            Castiel didn’t wait any longer.  He felt to make sure the bronze knife was in his pocket and then he was gone.

            After her left a silence descended for a couple seconds. And then…

            “Hey, Dean.  Are we friends?”

            “Yeah sure, kid.”

            “Nice.”

            Dean nodded, glad the conversation had ended and he could focus on the matter at hand.

            “So do you really like Cas?”

            Dean sighed.  He considered for a moment just ignoring him completely but Peter no doubt had more uncomfortable conversation starters up his sleeve.

            “Look, Cas told me all about the soulmate thing.”

            “Good!” Peter said excitedly.  “Aren’t you excited to meet them?”

            Dean couldn’t help but feel a bit sorry for him.  He was really into this whole ‘love’ thing.  Dean took a deep breath.

            “Listen…Cas wasn’t allowed to tell you this, because of heaven’s whole protocol thing, but I have no reason to keep it from you so I’m just gonna go for it.”

            Dean could see the confusion written in Peter’s eyes, but he just nodded and waited for whatever Dean wanted to say.  Dean took another deep breath.

* * *

 

            Castiel landed in the compartment Peter had told him about.

            Empty.

            He stared around in shock.  The window had been smashed in and the wind from outside was rushing violently throughout the room, whipping his coat back and forth along with it. 

            Which placed the Siren somewhere outside, probably the roof.

            Great.

* * *

 

            “You’re gonna be okay, man.”        

            “I just can’t believe it.”  Peter scuffed his sneakers against the floor.  “I mean, what’s gonna make you happy for the rest of your life?  Won’t you get lonely?”

            Dean ran his hands down his face.  “Nope.  I’ve got family and friends that I can visit if I ever need company.  And I’ve been pretty happy on my own, actually.”

            Peter scoffed and pointed at Dean’s chest.  “Then what’s with the heart-sickness, lover boy?”

            Dean scoffed sarcastically in return.  “Cas says it’s because I hate myself.  So…take that.”

            “You hate yourself?”  Peter looked down sadly and mumbled, “You wouldn’t be saying that if you could see your soul.”

            “What about my soul?”

            “It’s just really nice is all.  Even Cas was impressed.  That’s why he was staring at you earlier.”

            Dean was quiet for a moment, pursing his lips together.  “Cas thinks my soul is nice?”

            “Yeah.”  Peter narrowed his eyes.  “I knew you liked him.”

            “I don’t like Cas!”

            “Sure.”  Peter grinned, but it only lasted a second before sliding off his face.

            Dean bumped him with his shoulder.  “Okay, what’s really bothering you?”

            Peter just shook his head and looked down, so Dean bumped him again and nodded supportively.

            “It’s just, I’m not good…at a lot of things.  I can see how all the other angels look at me every time I mess something up.  And that’s a lot of the time.”  He looked over to see Dean waiting with a closed off expression before he went on.  “But this…it always came so easy.  I just find one person and lead them to another.  And I make them happy.  Forever.”  He took a deep, shuddering breath and when he continued his voice was a bit thicker.  “But what if it’s only easy for now?  Apparently I don’t even know the first thing about soulmates.  What if later it gets too hard and I’m not even good at the one thing I was supposed to be good at?  I just wanted something to be easy for once.”

            His voice broke on the last word and Dean immediately pulled him into a tight hug.  Peter buried his face in Dean’s neck and tried to take in deep breaths.

            “Look,” Dean started.  “I know for a fact that you’re gonna be the best Cupid heaven’s ever seen.” 

            Peter sniffled.  “No.”

            “Oh, yes I do.  I’ve seen you around people and if there’s one thing you’re good at, it’s love.  Even if you still have a lot to learn.” 

            Peter turned his head to the side, still pressing it against Dean’s chest.

“And even if you find out that you’re not good at being a Cupid, or it’s too hard for you, that isn’t all you have going for you.”

            “It’s not?”

            Dean shook his head.  “Nope.  Like…you’re a total klutz, according to Cas.”

            Peter pulled back and squinted at him in confusion.  “That isn’t a good thing.”

            “It is if you try to be the best klutz heaven’s ever seen.”

            Peter scrutinized him for a moment and then laughed, quietly of course.  Dean waited until it died down.  “I know what it’s like to try to be something you’re not because other people want you to be.  And it sucks.  And you’ll regret it if you let it go on too long.  Sometimes you just gotta take whatcha got and roll with it.”

            Peter mulled over this for a few moments.  Outside someone hurried past the door, and everything was silent again.

            “Are you gonna stop trying to be something you aren’t then?”

            Dean’s head snapped back over to Peter.  “Sorry?”

            “Cas was right.  You don’t have a responsibility to any of the people you help.”

            “Wait a minute –“

            “Anything you do for them is a kindness on your part.  And since the only thing you can give them is your best, if that isn’t enough then there’s nothing more you can do.  And even that’s more than you had to do in the first place.”

            Dean didn’t know what to say in response to that, and instead turned to face the closet door again. 

            “It’s been a couple minutes.  Should we go after him?”

            “Yeah I guess.”

* * *

 

            Castiel stood still on the roof of the train.  He could feel the siren in the car below him.  He could also feel his rising frustration by the second.  Peter was right about this being an ‘evolved’ breed of Siren.  Not only was it incredibly fast, fast enough to evade even him, it had also developed the ability to sense when an Angel was nearby. 

            It led him on a wild goose chase from where they started all the way back to the cab, ducking through windows and weaving its way through carriages and back onto the roof.  In its wake it left a trail of shocked, confused, windswept passengers clutching at hats and bags and rushing into the corridor wondering what was happening. 

            He heard a window shatter loudly to his right and spun around, ready to rush the creature as soon as it slipped up and showed its face.  He waited and waited and waited.  The blunt object slamming into the back of his head was…unexpected, to say the least.

* * *

 

            Peter gripped tightly to Dean’s wrist, pulling them through the crowded corridors and shoving past the people in their way.

            “Peter! What happened?!”  Dean hoped his voice would carry over the sound of the wind rushing through the train.  One woman swung her purse and smacked him violently in the face.

            “I don’t know!  I can feel them moving toward the cab of the train!  I think –“  Peter froze.  Dean slammed into the back of him before grabbing his shoulders and steadying them both. 

            “Castiel’s gone.”  The words were quiet and if Dean hadn’t been right next to him he’d have missed it.

            “What do you mean gone?  Where did he go?”

            “I don’t know, but he’s not here anymore!  He’s getting further away.”  Peter shook his head and took off down the corridor once again.  “The siren’s at the cab now, we can’t wait for him!”

            When they arrived at the door Dean clamped his hand onto Peter’s shoulder and pulled him back.  “I’m going in.  Stay out here unless I explicitly call for you.”

            “What?  Dean, I’m the one who can see who the siren is.”

            “This isn’t your fight.  If you got hurt Cas would skin me alive.  Stay here!”

            “That’s barbaric!”  He didn’t even get the words out before Dean had slipped into the cab.


	7. Chapter 7

**Summary for the Chapter:**

> Peter just wants to find Dean's soulmate, which isn't a problem except that it's impossible. Of course it ends up being Castiel's problem because when has luck ever been on his side? Meanwhile Dean just really wants to take down a siren.

Dean stepped into the quiet of the cab and looked around the small space.  There was one large window stretching across the whole front, along with the control panel he’d gotten a glimpse of earlier.  And there, in front of the panel, in the engineer’s chair…was Janelle.  Except she had removed her hat and let her hair fall around her shoulders like a curtain.

            “Janelle?”

            The woman in question turned in her seat and smiled at him.  “So glad you could finally join us, Dean.”  He only had a moment to notice the glint in her eyes before something was swinging towards his head from the right.

            Dean ducked on instinct and leaped back, colliding with the cab wall that was closer than he expected and knocking the wind out of himself momentarily.  One moment was just enough time for Martha to grab the front of his jacket and throw him onto the ground.

            He rolled over, ready to kick her away when the Siren’s foot collided with the side of his head and the room started to spin.  He blinked lazily and tried to bring his eyes back into focus, but then Martha’s weight was settling on top of him and…yeah that was definitely the point of a knife pressing against his throat.

            Dean tried to pry one of hands free from where they were pinned by Martha’s knees, quite painfully, in order to reach the bronze knife.  The bronze knife that was currently still with Castiel.  Who was apparently…no longer on the train.

            _Stupid, Winchester_.  He never should have come in here.  His pulse started to race as Janelle - no, the siren crouched down next to his head.

            “What did you do to Janelle?”

            She laughed.  “Nothing.  Yet.  She’s with all the other staff trying to figure out why the windows are ‘malfunctioning’.”  She ran one finger slowly down the side of Dean’s face.  “I’ll take care of her once you and the angel brigade are gone.”

            Dean’s eyes flickered to the door.  The siren’s eyes followed.  A lecherous grin spread across her face and she tutted.

            “I know he’s there.  Peter!  Come on inside and I can tell you all about what I did to your other friend.”

            They watched with baited breath for the door to move, but it stayed still. 

            _Good, kid._

            The siren shrugged and stood up again.  “Suit yourself.  We’ll have all the fun in here without you.” 

            “You’re dead,” Dean spit out at her.

            Her face didn’t even change expression.  “Martha, make him pay for that.”

            Martha ran the blade from below Dean’s ear down to the bend of his neck.  He sucked in a sharp breath as pain exploded on the left side of his face and felt blood pour from the wound.

            “Isn’t she so good to me?”  The siren stepped around them until she was in front of the door. Martha preened a bit at her words, still not taking her eyes off of Dean.  “It’s a shame I can only keep her until our next stop.”

            “Martha, that isn’t Janelle.  Please don’t listen to her.”  His words were strained and gasping, and Martha only narrowed her eyes at him.

            The Siren threw her head back in laughter.

            Castiel chose that moment to appear on the ground next to the two of them, causing both Dean and Martha to jolt at his sudden presence.  In one fluid motion Cas twisted her wrist face up and sliced the bronze dagger along her forearm.

            Martha screeched in pain and yanked her arm away from Cas, giving Dean the chance to throw her off of him.  She collided with the siren’s legs and was promptly kicked away with a snarl.

            “Completely useless.”  Her eyes locked back onto Cas and the blood soaked blade clutched in his right hand.  She smirked.  “You weren’t faster than me before, but be my guest.”

            Dean rolled over and tried to stand, but Martha grabbed onto his legs and dragged him back down.  The pain in his neck intensified and he gasped.  He looked back, trying feebly to kick her away and froze as he saw the door behind the siren inching open.

            _Peter, no, please_.

            When Castiel said nothing to her, the siren sighed.  “Am I going to have to do all the work myself?”  She cast a shallow glance towards Martha and Dean struggling on the floor.  “I’ve been waiting days to kill the hunter, but I think you might be more satisfying in the end.”

            Dean stopped breathing when it happened.  The siren’s eyes widened a fraction, realization that someone was behind her, just before a pair of arms were shoving her forward right into Castiel’s blade. 

            She fell to the floor. Castiel stepped away from her as choking noises gurgled from her throat.  It only took a few seconds until she stopped moving and nobody in the room was willing to move for several moments after.

            Then Janelle stepped into room, staring at her fallen doppleganger with a blank look. 

            Martha let out a small noise of distress at the sight of her, pulling Janelle’s attention down to where she and Dean were still kneeling on the floor.

            “Oh, my God, are you bleeding?”

            Martha’s mouth opened and closed a few times before she squeaked, “Who was that?”

            Janelle pulled her up to her feet and started inspecting her wound.  “I’ll tell you everything as soon as we get this bandaged.”

            Castiel stepped forward, making sure to drop the knife in his coat pocket.  “I can actually take care of that, if you’ll let me.”  He tried to make his words as gentle as possible.

            Janelle looked him up and down.

            “You’re like the boy?  The one that…materialized in front of me a few minutes ago?”

            Castiel nodded and Janelle nodded back.  “Go on,” she urged Martha with a steady hand on her lower back. 

            Martha stepped forward uncertainly but held out her hand for Castiel.  He took it carefully in his own and they all watched in fascination as the large gash down her arm sealed shut.  She stared at it in shock, then looked down at the dead Siren and back up at Cas.

            “This wasn’t in my job description.”

            Janelle pulled her close, folding her into her arms and into a deep kiss.  Dean and Cas both looked away to give them a moment of privacy, and Dean pointed to the gash on the side of his neck and said, “I’ll have what she had.”

            Castiel laid his hand across the back of Dean’s neck, rubbing his thumb through the short hairs at the base of his scalp.  Dean sighed as he felt the stinging pain leech from his neck, followed by the throbbing in his head he’d completely forgotten about. 

            Just then, Lin walked into the room.  She took one look at the body on the floor and glared at Dean and Cas.

            “I don’t understand what’s going on but I want someone to take care of that right now.”  She looked past them and took in a sharp breath.  “And why is nobody driving my train?!”  She rushed past them and plopped herself down in front of the control panel, glancing back at Martha and Janelle.

            “Why don’t you two take a fifteen minute break?  I’ll have Marcus take care of the passengers for now.”

            “Thank you,” Martha whispered as she and Janelle left the room.

            Dean and Cas slowly started to follow them, but Lin spun around and pointed an accusatory finger at them.

            “Not you two!”  She looked at the body and then back at them.  “You’re going to explain yourselves and then clean up my train.”


	8. Chapter 8

**Summary for the Chapter:**

> Peter just wants to find Dean's soulmate, which isn't a problem except that it's impossible. Of course it ends up being Castiel's problem because when has luck ever been on his side? Meanwhile Dean just really wants to take down a siren.

            “I’m glad this is over.  Dead bodies are gross.”

            Dean threw Peter a deadpan look.  “You didn’t even have to touch it.”

            “Still gross,” he said, shaking one of his legs up and down rapidly.  Probably adrenaline, Dean decided.

            “How did you know the siren wouldn’t be able to sense a human anyway?”

            “Oh I figured it could.”  At Dean’s questioning look he explained, “It’s a lot harder to feel a human soul than an angel’s grace.  Our grace is just…bigger.  Louder.  So I assumed she’d be too distracted to pay attention to a human soul sneaking up on her.”

            “That was very clever,” Cas said, stepping into the carriage with them.  “And reckless.  You put her in a lot of danger.”

            Peter looked a bit sheepish.  “Yeah, well…she was the only plan I could come up with.”

            “Did you tell her thanks for that, by the way?” Dean asked.

            Castiel flushed.  “I didn’t actually.  I didn’t want to disturb her…and Martha.”

            Dean whistled low and Peter let out a quiet, “Awe.”

            Castiel hurried to continue.  “Lin said she’s willing to look the other way while we disappear, and she can lose your boarding information, Dean.”

            Dean clapped his hands together.  “Great.  So how does this work, then?  You just fly me back to my car, leave your cellphone numbers and we go our separate ways?”

            “Well,” Cas tilted his head thoughtfully, “I can fly you back to your car but we don’t have cellphones in heaven.”

            Dean stared at him.  Peter coughed. 

            "Cas, he’s just saying he wants to stay in touch.  Right?”

            “Well, I’m not gonna let you miss Sammy’s wedding.”

            Peter grinned and threw his arms around Dean’s neck once again, pulling back to plant a kiss on one of his cheeks.

            Dean rubbed the spot he’d kissed and said, “That’s gonna take some getting used to.”

            “Cupids,” Cas agreed.

            Dean looked up at him and smiled.  “What about you?  You’re not gonna forget about me, are you?”

            Castiel licked his lip and looked away.  “I’m very busy…with things.”

            “Then change your plans,” Peter whined.  He slid across the bench and threw one arm around Dean’s shoulders.  “Come on, Cas.  He likes you.”

            “I do not!”

            Cas frowned.

            “Okay…I mean I like you but – I don’t like, have a thing for…,”  he gestured vaguely in Cas’s direction.

            Cas frowned harder.

            Dean coughed.  “Weren’t you guys supposed to fix my soul, or something?”

            “Don’t worry about that! It fixed itself a while ago.”

            Dean looked at him in shock. 

            “He’s right,” Cas said, eyes trained on Dean’s chest.  “I don’t know how but the stain is gone.”

            “Also,” Peter said, holding up a hand to grab Cas’s attention, “he told me all about the soulmates thing so you don’t have to worry about that.”

            “I’m in so much trouble,” Cas muttered to himself.

            Dean wasn’t listening to either of them anymore.  Instead he was resting his palm against his heart, feeling his chest rise and fall with each breath.  When he was them both watching him he shrugged sheepishly.

            “Yeah, I feel good.  I mean – maybe not great, but…I’m okay.”  He nodded to himself.  “I’m okay.”

            He smiled at Castiel, and Castiel smiled back.

            “I’d probably be better if you promised to come back sometime.”

            Castiel would insist for years to come that the only reason he agreed was due to the combined pouting of both Dean and Peter.  Nobody ever believed him though.

 


End file.
